Key Laboratory of Characteristics Garden Plants Resource in Fujian and Taiwan, School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, PR China.
Key Laboratory of Characteristics Garden Plants Resource in Fujian and Taiwan, School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, PR China.
Int J Biol Macromol. 2020 Dec 15;165(Pt A):198-204. doi: 10.1016/j.ijbiomac.2020.09.195. Epub 2020 Sep 28.
In this study, native pectin (Na-Pe) was acylated with gallic acid through enzymatic method. UV-Vis, Fourier transform infrared spectroscopy and proton NMR analyses demonstrated that the phenolic hydroxyl group on gallic acid attacked the carbomethoxy of Na-Pe and replaced the methoxy group to form a new ester group under catalysis. The galloyl content of acylated pectin prepared via 24-h reaction (Ac1-Pe) was 16.8%, while that prepared via 48-h reaction (Ac2-Pe) reached 20.7%. The emulsifying properties, antioxidation activities and antibacterial activities of acylated pectin was significantly improved compared with those of Na-Pe. The emulsion activity and emulsion stability of the pectin emulsion improved from 1.08% and 56.13% (Na-Pe) to 1.57% and 88.27% (Ac1-Pe) and 1.71% and 93.3% (Ac2-Pe), respectively. The DPPH clearance of the pectin improved from 2.68% (Na-Pe) to 68.92% (Ac1-Pe) and 76.98% (Ac2-Pe) and the inhibition ratio in the β-carotene bleaching assay of the pectin increased from 3.15% (Na-Pe) to 73.02% (Ac1-Pe) and 78.96% (Ac2-Pe). The inhibition rate of the pectin against Escherichia coli and Staphylococcus aureus also improved from 2.93% and 8.92% (Na-Pe) to 26.95% and 42.18% (Ac1-Pe) and 31.56% and 47.87% (Ac2-Pe), respectively.
在这项研究中，通过酶法将天然果胶（Na-Pe）与没食子酸酰化。紫外可见光谱、傅里叶变换红外光谱和质子 NMR 分析表明，在催化条件下，没食子酸上的酚羟基攻击 Na-Pe 的甲氧基羰基，取代甲氧基形成新的酯基。通过 24 小时反应制备的酰化果胶（Ac1-Pe）的没食子酰基含量为 16.8%，而通过 48 小时反应制备的酰化果胶（Ac2-Pe）达到 20.7%。与 Na-Pe 相比，酰化果胶的乳化性能、抗氧化活性和抗菌活性显著提高。果胶乳液的乳化活性和乳液稳定性从 1.08%和 56.13%（Na-Pe）提高到 1.57%和 88.27%（Ac1-Pe）和 1.71%和 93.3%（Ac2-Pe），DPPH 清除率从 2.68%（Na-Pe）提高到 68.92%（Ac1-Pe）和 76.98%（Ac2-Pe），而对β-胡萝卜素漂白试验中果胶的抑制率从 3.15%（Na-Pe）提高到 73.02%（Ac1-Pe）和 78.96%（Ac2-Pe）。果胶对大肠杆菌和金黄色葡萄球菌的抑制率也从 2.93%和 8.92%（Na-Pe）提高到 26.95%和 42.18%（Ac1-Pe）和 31.56%和 47.87%（Ac2-Pe）。
